JPH0443542A - Particle beam irradiation device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for performing particle beam irradiation such as ion implantation onto a wafer.

In recent years, semiconductor devices have been required to be increasingly miniaturized, and metal contamination countermeasures are becoming increasingly important, especially as contamination with metals during the wafer process reduces the reliability of semiconductor devices. It's coming.

Therefore, even in the wafer ion implantation process, it is necessary to significantly reduce contamination of metals such as aluminum due to sputtering of the disk constituting the ion implantation apparatus, contamination due to sublimation of adsorbed molecules, and cross contamination.

[Conventional technology]

FIG. 4 shows a configuration diagram of a conventional ion implantation device (mechanical scan method), and FIG. 4(A) is a plan view, and FIG.
B) is a side view. In the figure, 1 is a disk made of aluminum, for example, and the rotation speed is 11000 rpm around the rotation axis.
rotates at a constant speed of 3+, 3*, . . . are wafer pads fixed on the disk 1 along the circumference. 4
．． ．． 4. . . . is the crumbling, and each wafer pad 3. .

3,... are provided at the upper end of the wafer 5.3, as shown in FIG. Clamp... 6 is a beam current measurement slit, which connects the wafer pad 31 and 3. A Faraday cup (not shown) is provided on the back side of the disk 1 through which the ion beam passes.

Here, when performing ion implantation, a wafer pad 3. ．． 3. 5 wafers each.・
4. Attach and crumbling. .

4. Clamp each wafer with... In this state, the disk 1 is rotated and an ion beam is irradiated as shown in FIG. As a result, ions are implanted into the wafers 51.

[Problem to be solved by the invention]

By the way, in order to spread the ion beam over the entire surface of the wafer, the ion beam is applied to the wafer 5. as shown in FIG. Generally, the ion beam is scanned over a slightly wider area than the area where the ion beam exists, so that the ion beam is also irradiated onto the disk l. Therefore, when the disk 1 is sputtered with an ion beam, aluminum atoms or atomic groups, etc., which are the constituent material of the disk 1, are released from the disk 1 and the wafer 5. adsorbs to the surface of
Atoms such as phosphorus, boron, arsenic, etc. in the ion beam are implanted into the disk 1, and during the next ion implantation of a different type, these implanted atoms are knocked out by the ion beam sputtering and are then deposited on the wafer 5. Wafer 5. However, metal contamination and cross-contamination may occur, reducing device reliability.

An object of the present invention is to provide a particle beam irradiation apparatus that eliminates metal contamination and cross-contamination and can manufacture highly reliable devices.

[Means to solve the problem]

In the present invention, a support mechanism for supporting a wafer pad has one end connected to a surface opposite to the particle beam irradiation surface of the wafer pad, extends substantially parallel to the particle beam irradiation direction, and has a cross-sectional area It is provided with a columnar support portion smaller than the beam irradiation surface.

[Effect]

Discs (e.g. made of aluminum) that make up the support mechanism
When the disk is hit by an ion beam, aluminum atoms or atomic groups are ejected from the disk, or implanted atoms of phosphorus, boron, arsenic, etc. that are implanted in the disk are knocked out.

In the present invention, since the wafer is mounted on a wafer pad that is supported by columnar supports apart from the disk surface that constitutes the support mechanism, aluminum atoms or atomic groups sputtered and emitted from the disk and sputtered The implanted atoms do not reach the wafer and do not cause metal contamination or cross-contamination on the wafer surface.

〔Example〕

FIG. 1 shows a configuration diagram of a main part of an embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a side view. In the same figure,
10 is, for example, an aluminum disk with a diameter of 1 m,
It rotates around the rotating shaft 11 at a constant speed of 1000 rpm. 12. , IL... is a wafer pad, and disk 1
For example, aluminum columnar support parts 131, 13. ...Disk IO on the top surface
It is provided either parallel to or at a slight angle of about 10° or less. Column-shaped support part 13. ...is the second
As shown in the figure, the wafer pads 12 □ . 14.

14! . . are clamping rings, which are provided at the upper ends of the wafer 1 pads 121, 121, . . . , respectively, and clamp the wafers 151, . . . as shown in FIG.

Reference numeral 16 denotes a beam current measurement slit, which is provided on the disk 10.

FIG. 3 shows an overall configuration diagram of an embodiment of the present invention, and in the figure, the same components as those in FIG. 1 are given the same numbers and their explanations will be omitted. In FIG. 3, 20 is an end station chamber in which the apparatus shown in FIG. 1 is installed.

Reference numeral 21 denotes a Faraday cup, which is provided on the back side of the disk 10 at a position opposite to the rotation locus of the slit 16.

Cryopumps 22a and 22b suck molecules released or knocked out from the surface of the disk 10, as described later. 23 is a load lock, 24 is an ion source, 25 is an analyzer magnet, and 26 is a Q lens (beam focusing lens). Here, the ion beam from the ion source 24 enters the Q lens 26 via the analyzer magnet 25 and is focused there, and the end station chamber 20
The wafers 15+... are irradiated.

As shown in FIG. 2, while the ion beam is irradiated onto the wafer 151 for the reasons mentioned above, it is also irradiated onto the disk 10 that constitutes the support mechanism.

In particular, aluminum atoms or groups of atoms are ejected from the disk 10 by sputtering the disk 10 with an ion beam, or implanted atoms such as phosphorus, boron, arsenic, etc. are knocked out of the wafer 15. is the columnar support part 13. 5an- from the surface of the disk 10 by
Since the cryopumps 22a and 22b are provided near the disk 10, the ejected aluminum atoms or atomic groups and the ejected cross-contamination atoms do not reach the wafer 15°. Before that, it is sucked in by cryopumps 22a and 22b. As a result, wafer t5. No aluminum atoms or atomic groups will be attached to the surface of the , and no cross-contaminating atoms will be re-implanted, i.e.
A highly reliable device can be obtained without causing metal contamination or cross-contamination, and the yield can also be improved.

In this embodiment, an example in which the support mechanism is a rotating disk has been described, but it goes without saying that the present invention can be widely applied regardless of the material and shape of the support mechanism.2 Regardless of the presence or absence of a rotation mechanism.

〔Effect of the invention〕

As explained above, according to the present invention, wafers are not subject to metal contamination or cross contamination, and as a result, quality can be improved and highly reliable devices can be obtained, contributing to device miniaturization. Moreover, the yield is improved and manufacturing is possible at low cost.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main parts of an embodiment of the present invention, Fig. 2 is a diagram for explaining the effects of the present invention, Fig. 3 is a block diagram of the entire present invention, and Fig. 4 is a diagram of the conventional An example of a configuration diagram, FIG. 5, is a diagram for explaining conventional problems. In the figure, 0 is the optical disk, l is the rotation axis, 2,,! 2. ... is Wafer Bud, 31.13. . . . is a support portion, 5, . . . is a wafer 20 is an end station channel, 22a, 22b
24 represents a cryopump, and 24 represents an ion source. Patent applicant: Fujitsu Limited Fujitsu Tohoku Electronics Ltd.

Claims (1)

[Claims] A wafer pad (12_1,...) that holds a particle beam irradiated wafer (15_1,...), and a support mechanism (10) that supports the wafer pad (12_1,...)
In the particle beam irradiation apparatus, the support mechanism (10) has one end connected to a surface of the wafer pad (12_1,...) opposite to the particle beam irradiation surface, and is substantially parallel to the particle beam irradiation direction. Column-shaped support portions (13_1, . . .
...) A particle beam irradiation device characterized by comprising: